perhaps the timing is OK. I swapped out the suspect coil and seems much better, but it starts and idles fine with choke pulled. when choke is released, it dies. My trouble shooting thoughts: too large main jet or a massive air leak/fuel starve.

The main jet is a 120. specs on scooterhelp.com say 108 for a main. I checked two other GS carbs I have and they all have 120 mains...

or a massive air leak... or lack of fuel. fuel flow to the carb seems right.